Recent years have been witnessing the development of display devices that allow their users to perceive a stereoscopic image (video) by displaying a three-dimensional image (three-dimensional video) taken by exploiting binocular parallax (see, for example, Patent Document 1 listed below).
Patent Document 1 discloses a stereoscopic image display device that employs a pair of liquid crystal shutter glasses (active shutter glasses), that is, one that adopts the so-called frame-sequential method. This stereoscopic image display device displays images for the right and left eyes alternately. While the right-eye image is being displayed, the right eye-side shutter of the liquid crystal shutter glasses alone remains released; while the left-eye image is being displayed, the left eye-side shutter of the liquid crystal shutter glasses alone is remains released. This permits the right-eye image to be shown to the right eye alone and the left-eye image to be shown to the left eye alone, and thereby allows the user to perceive a stereoscopic image.
Such display of three-dimensional video by the frame-sequential method can be implemented in liquid crystal display devices incorporating liquid crystal display panels, and recent years have been seeing the introduction of television receivers that incorporate liquid crystal display devices capable of displaying three-dimensional video.
Seeing, however, that, of the currently available video content, overwhelmingly most is two-dimensional, taken from a single viewpoint, and only a fraction is three-dimensional, it is preferable that liquid crystal display devices (television receivers) as mentioned above be configured so as to be capable of displaying both two-dimensional and three-dimensional video.